Thick Lens Formula -- from Eric Weisstein's World of Physics

The above figure is Figure 2.5, p. 13, from Schroeder (1987). Applying the equation of paraxial refraction with n' = 1 (air) to each surface gives {n_m\over s_{o1}} + {n_l\over s_{i1}} = {n_l-n_m\over R_1} {n_l\over s_{o2}} + {n_m\over

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